Mounting of alarm switches to valves

ABSTRACT

An alarm switch for a control valve (5) is disclosed which has resilient fingers (37) extending from a casing (1) thereof. The fingers (37) are attachable to a yoke (23) of the valve (5) and resiliently deflect to accommodate for minor variations of yoke widths between different valves (5) and support the casing (1) in a position centrally across said yoke and in alignment with the central longitudinal axis of the valve shaft (3). This, in turn, can permit adjustment of the position of the casing (1) relative to an appropriate sensing initiating means carried by the valve shaft (3). Brackets (45) can be used to hold the casing (1) fixed to the yoke (23) so that when a correct position is obtained the casing (1) can be securely held in that position.

FIELD OF THE INVENTION

This invention relates to mounting of alarm switches to valves andrelates particularly, but not exclusively, to an alarm switch withmounting means and to a method of mounting such a switch to a risingstem type water supply valve so that the alarm switch can monitor theopen and/or closed condition of said valve.

DESCRIPTION OF PRIOR ART

I already have patents in Australia relating to alarm switches for watersupply valves. I make reference to Australian Standard Patent No.567,040 and to Australian Petty Patents Nos. 549,439 and 551,017, thesubject matter of which is hereby incorporated by reference.

It has been found particularly troublesome to correctly align the alarmswitch relative to the valve stem or valve shaft in valves owing to therather peculiar structure where the spacing apart of the side sectionsof yokes which support the valve shaft are different between valves.Such yokes are also inclined relative to the central longitudinal axisof the valve shaft. This, in turn, makes for complicated mounting means.The problem is further exacerbated by the fact that the angle ofinclination of the sides of the yokes are different between valves madeby different manufacturers. Hence, it is generally accepted that a largerange of mounting brackets are needed to accommodate mounting of suchalarm switches to all valves regardless of manufacturer.

OBJECT AND STATEMENT OF INVENTION

It is therefore an object of the present invention to attempt to providean alarm switch with mounting means which can reduce, at least to somesmall degree, the aforementioned problem. A method of mounting such analarm switch is also within the general object of the invention.

Therefore, according to a first broad aspect of the present inventionthere may be provided an alarm switch of a type which is externallymountable to a control valve for sensing of the open and/or closed stateof said valve, said alarm switch having a casing in which is carried aswitch means for providing such sensing when mounted to co-operate withan appropriate sensing initiating means associated with a valve shaft ofsaid valve, said casing having two resilient mounting fingers one on oneside and the other on an opposite side, said mounting fingers beingmountable to a yoke part of said valve, the resiliency of each fingerbeing such that the fingers will resiliently deflect to accommodate forminor variations of yoke widths so that said casing will be centrallydisposed across said yoke and in alignment with the central axis of thevalve shaft of said valve.

According to a further broad aspect of the present invention there maybe provided a method of mounting an alarm switch to a fluid supply valvefor sensing the open and/or closed state of said valve, said alarmswitch being contained within a casing, said method comprising:

(a) attaching one resilient finger to one side of a yoke of said valve,

(b) attaching a second resilient finger to an opposite side yoke of saidvalve so that a valve shaft of said valve is centrally between thefingers,

(c) attaching each of the fingers to respective opposite sides of saidcasing so said casing will be centrally disposed across said yoke and inalignment with the central axis of said valve shaft, said resilientfingers being resiliently deflected when said casing is so disposed, theresiliency being sufficient to accommodate for minor variations in yokewidths.

The order of attachment of the fingers to the yokes and to the casingmay be reversed and this is to be understood to be within the scope ofthe invention.

Most preferably the fingers are attached to the casing by positionadjusting attachment means so that by appropriate adjustment thereof,the casing can be attached correctly relative to said valve shaftwhereby to accommodate for minor variations in yoke widths in valves.

Most preferably there are provided two mounting brackets which can thenbe attached to said casing--one on each side--and to said yoke tosecurely fasten and hold said casing in a correct operational positionrelative to said shaft.

BRIEF DESCRIPTION OF DRAWINGS

In order that the invention can be more clearly ascertained, an exampleof a particularly preferred embodiment for use on a rising stem watersupply valve will now be described with reference to the accompanyingdrawings, wherein:

FIG. 1 is a close-up side, partly broken away, view of an upper yokepart of a rising stem water supply valve showing how the preferred alarmswitch and its casing are positioned relative to the valve shaft;

FIG. 2 is a close-up view similar to that of FIG. 1 where the brokenaway portion is shown in full and showing how a mounting bracket isdisposed;

FIG. 3 is a sectional view along line 3--3 of FIG. 1;

FIG. 4 is an exploded perspective view showing the various componentsused for mounting of the alarm switch and its casing relative to theyoke of the valve;

FIG. 5 is a front perspective view of the casing of the alarm switch;and

FIG. 6 is an underneath rear perspective view of the casing shown inFIG. 5 where a lid has been removed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference should now be made to the aforementioned Australian standardpatent specification and the aforementioned Australian petty patentspecifications for an understanding of the general concept of an alarmswitch. In a rising stem valve it is normal for the alarm switch toappropriately co-operate with the valve shaft in order to sense if thevalve is open or closed. This may be achieved by providing a drilledhole transversely into the valve shaft at an appropriate position andplacing appropriate magnetic material in the hole. In such case thealarm switch contains a magnetically operable sensor which senses thepresence of the appropriate magnetic material. Other variations of alarmswitch work by having a switch such as a microswitch co-operate with anopening and/or a projection on the valve shaft. In such instances, themicroswitch is caused to trip to change its state when the valve shaftis moved and as a result of the opening and/or projection coacting withthe microswitch.

In all types of alarm switches, the mounting of the casing in a correctoperational position relative to the valve shaft is critical.

Therefore, the present embodiment of the invention provides a means foraccomplishing mounting of the casing of the alarm switch in asubstantially correct operational position relatively easily whereby toaccommodate for minor variations in yoke widths between valves. In thisway it is possible to provide an alarm switch and a casing therefor withmounting means which will enable the alarm switch and its casing to besubstantially correctly positioned relative to the central axis of thevalve shaft for a wide range of different valves. Thus, it will not benecessary to carry particular mounting brackets for each type of valve.

Referring now to all of the figures in the drawings it can be seen thatthere is provided a casing 1 in which the alarm switch can be contained.The alarm switch and its associated circuitry have not been shown in thedrawings as these are not critical to the present invention. The alarmswitch may comprise magnetically operable switches, proximity switchesand/or microswitches or any other form of switch suitable forco-operating with the valve shaft 3 of a valve 5 or a part carried bythe valve shaft, so as to sense when the valve is open and/or closed. Inthe preferred embodiment they comprise magnetically operable switches.

The casing 1 comprises a main body 7 and a lid 9. The body part 7 has anupper angularly inclined opening 11 (see FIG. 6) to permit easy accessto the interior of the casing 1 to facilitate easy connection toelectrical terminals for the alarm switch. The lid 9 has acorrespondingly inclined lid portion which is provided to snap lockengage over the base 7. This is shown particularly in FIG. 6. In thisconnection the lid 9 has four cut-outs 13 therein which snap lock engageover four projections 15, only two of which are shown in FIG. 6. Thus,the lid 9 can be secured to the base 7. Appropriate magnetic materialcan be mounted within an elongate recess 17 in the lid 9 to co-operatewith a magnetic sensor within the alarm switch mounted within the body7. Thus, if the lid 9 is removed the alarm switch will indicate an alarmcondition. This provides for tamper-proof mounting of the lid 9 relativeto the body 7. The body 7 of the casing 1 has a forward end 19 with acentrally located arcuate cut-out 21. The forward end 19 is disposed, inuse, towards the valve shaft 3 so that the arcuate cut-out 21 partlyreceives the valve shaft 3 therein. This, in turn, will provide forsubstantially correct location of the casing 1 relative to the centralaxis of the valve shaft 3 so the alarm switch therein can correctlyco-operate with the valve shaft 3. In other words, the cut-out 21locates the casing 1 centrally across a yoke 23 of the valve 5. This isclearly shown in FIG. 3.

At each side of the casing 1 there is provided a recess 25 which is openfrom the forward end 19. The recesses 25 are clearly shown only in FIGS.4, 5 and 6. An elongate slot 27 is provided on each side of the casing 1and provides a communication with the respective recess 25 at each side.

Each of the recesses 25 and slots 27 is provided to respectively receiveposition adjusting means 29 (shown most clearly in FIG. 4). As can beseen, the position adjusting means 29 comprise a rectangular shaped nut31 with a centrally disposed upstanding boss 33. The nut 31 is providedfor sliding in the recess 25 whilst the boss 33 is provided for slidingwithin the elongate slot 27. The position adjusting means 29 carries ascrew-threaded bolt 35 which is screw-threaded into the nut 31.

A pair of resilient fingers 37 are provided so that one can be fastenedto one side of the casing 1 and the other to the other side of thecasing 1 to extend from the forward end 19. As can be seen in FIG. 4,the fingers are elongate and have a forward clip 39 formed integrallytherewith. The forward clip 39 is provided for, in use, clipping overone side edge of the yoke 23. This is shown in FIGS. 1 and 3. Theresilient fingers 37 have an elongate slot 41 of a width just slightlysmaller than the diameter of the boss 33 so that they can be carriedunder a head 34 of the boss 33. A cut-out 43 is provided in the finger37 which communicates with the slot 41 so as to enable easy passing ofthe head of the bolt 35 through the slot 41 as well as for the easypassing of the head 34 of the boss 33 through the slot 41.

When the position adjusting means 29 is positioned within the recesses25 and the respective fingers 37 fastened thereto, the boss 33 can beslid along the slots 41 in a frictional manner whereby to hold thefingers 37 at a partly secured position extending forwardly of theforward end 19 but within the recesses 25 as shown in FIGS. 1 and 3.

In order to mount the casing 1 relative to the yoke 23, the casing 1with the forwarding extending resilient fingers 37 is then placedbetween the sides of the yoke 23 and in approximate alignment with thevalve shaft 3. The forward clips 39 are then clipped over the sides ofthe yokes 23, as shown in FIG. 3, so that the casing 1 will be held in asubstantially central position so that the arcuate cut-out 21 is locatedcentrally with the axis of the valve shaft 3. The resilient fingers 37can be deflected somewhat, if needed, to accommodate for the width ofthe yoke 23. The resilient fingers 37 and the casing 1 can then be slidup and down the yoke 23 to an appropriate position to align with theappropriate means on the valve shaft to initiate the necessary sensing.When the correct position is found, then the nature of the fingers 37and the forward clips 39 is such that it will hold the casing 1 in therequired position.

It is noted that in order to establish a final correct position for thecasing 1 the casing 1 may be required to be angularly rotated relativeto the longitudinal extent of the fingers 37 and that it may be requiredto be moved in and out relative to its elongate slots 27 and/or theslots 41 in the fingers 39. The position adjusting means 29 will enablethis to occur.

To securely hold the casing 1 in the correct position there are providedtwo mounting brackets 45. One mounting bracket 45 is mounted on one sideof the casing and the other is mounted on the other side so that therespective bolts 35 pass through respective openings 47 therein toattach the brackets 45 relative to the casing 1. It is required that thebase 49 of the mounting brackets 45 locate against the edge surface ofeach yoke 23. This is clearly shown in FIG. 2. A hole 51 (see FIG. 4)can then be drilled through the base 49 and into the sides of the yokes23 and a locking drive pin (not shown) inserted through the holes 51 tolock each of the respective mounting brackets 45 to the yokes 23. This,in turn, will securely lock and hold the casing 1 to the yokes 23 and ifthe initial adjustment has been made correctly, it will positively holdthe casing 1 in the correct operational position.

Thus, it can be seen that with the above arrangement it is possible toprovide for mounting of the casing 1 to valves to accommodate for minorvariations in widths of the yokes 23. This is because the resilientfingers 37 can be flexed to accommodate for such minor variations inwidths.

If the angle of inclination of the yokes 23 is different between valvesthen the mounting means 29 will still permit the casing 1 to be properlypositioned.

FIG. 1 and FIG. 4 show that the position adjusting means 29 has twoupstanding pips 61 and 63 thereon, each on the face which will abut withthe face of the resilient fingers 37. Pip 61 is positioned immediatelyto the side of boss 33 whilst pip 63 is positioned on the opposite sideof boss 33 at the edge of the nut 31. In use, the position adjustingmeans 29 is slid to the end of slot 41 remote from the clip 39. The pip61 then engages with the end face of the resilient fingers 37 and causesthe head 34 to tightly engaging with the resilient fingers 37 tofrictionally hold the position adjusting means 29 at that positionduring initial assembly to the casing 1. This, in turn, allows thefingers 37 to project a maximum distance from the recess 25 for initialfitting to the valve 5. Should the position adjusting means fall to theother end of the slot 41, pip 63, being taller than pip 61, will engagewith the bottom edge of cut-out 43 and prevent the head 34 of the boss33 from passing into the cut-out 43, and thus permitting the positionadjusting means 29 to fall away from the finger 37.

The actual alarm switch can be mounted on a printed circuit board whichcan be arranged to slide fit within the base 7 and then be back-filledwith a suitable epoxy resin. A threaded opening 53 may be provided topermit conduit to be fastened to the casing 1 to contain wiring to theswitch circuit therein. If desired, the lid may be completely filledwith a sealastic or other suitable water-proofing material prior tofastening to the base 7 so as to inhibit ingress of water which mayotherwise electrically short the terminations made to the alarm switchtherein. If desired, a recess 55 (see FIG. 6) may be provided on thecasing in which may be located a LED which can give a visual indicationat the alarm switch casing 1 of an alarm condition being present oralternatively that the alarm switch is in an activated state ready forsensing an alarm condition.

The casing may be made from a suitable plastics material but othersuitable materials such as of metal or resins are not excluded.Typically the fingers 37 are made from a resilient steel but otherresilient materials such as plastics or the like are not to be excluded.

When a magnetic reed switch is used and the switch and appropriatemagnetic material such as a permanent magnet is carried by the valveshaft 3, the arcuate cut-out 21 may be moulded with thin webs or pips(not shown) which project say 1 mm from the arcuate face thereof. Thus,by pressing the casing 1 hard against the valve shaft 3, it willcorrectly space the casing a predetermined distance, in this case 1 mm,from the valve shaft. The thin webs or pips can then wear away as thevalve is used, as by frictional wear, without unduly affecting operationof the valve.

In the preferred embodiment herein it is preferred that the fingers 37be attached to the casing 1 prior to the fingers 37 being attached tothe yoke 23. The reverse procedure where the fingers 37 are attached tothe yoke 23 and then to the casing 1 is also possible and is to beconsidered within the scope of the invention.

Modifications may be made to the present invention as would be apparentto persons skilled in the alarm switch sensing art without departingfrom the ambit of the invention, the nature of which is to be determinedfrom the foregoing description.

I claim:
 1. An alarm switch of a type which is externally mountable to acontrol valve for sensing of the open and/or closed state of said valve,said alarm switch having a casing in which is carried a switch means forproviding such sensing when mounting to co-operate with an appropriatesensing initiating means associated with a valve shaft of saidvalve,said casing having two resilient mounting fingers one on one sideand the other on an opposite side, said mounting fingers being mountableto a yoke part of said valve, the resiliency of each finger being suchthat the fingers will resiliently deflect to accommodate for minorvariations of yoke widths so that said casing will be centrally disposedacross said yoke and in alignment with the central longitudinal axis ofthe valve shaft of said valve, and mounting bracket means, attached tosaid casing and located against said yoke, to securely fasten and holdsaid casing in a correct operational positional relative to saidappropriate sensing initiating means.
 2. An alarm switch as claimed inclaim 1 wherein said fingers are attached to said casing by positionadjustment attachment means so that by appropriate adjustment the casingcan be moved in and out relative to said valve shaft whereby to becorrectly operatively positioned to said appropriate sensing initiatingmeans.
 3. An alarm switch as claimed in claim 2 wherein said positionadjustment attachment means will permit said casing to be angularlyinclined relative to said fingers whereby to correctly operativelyposition said casing relative to said appropriate sensing initiatingmeans.
 4. An alarm switch as claimed in claim 1 wherein said resilientmounting fingers have clip means for permitting clipping to said yoke.5. An alarm switch as claimed in claim 1, wherein said mounting bracketmeans is attached to said yoke.
 6. A method of mounting an alarm switchto a fluid supply valve for sensing the open and/or closed state of saidvalve, said alarm switch being contained within a casing, said methodcomprising:(a) attaching one resilient finger to one side of a yoke ofsaid valve, (b) attaching a second resilient finger to an opposite sideof said yoke of said valve so that a valve shaft of said valve iscentrally between the fingers, (c) attaching each of the fingers torespective opposite sides of said casing so said casing will becorrectly operatively positioned relative to an appropriate sensinginitiating means associated with said valve shaft and be centrallydisposed across said yoke and in alignment with the central longitudinalaxis of said valve shaft, said resilient fingers being resilientlydeflected when said casing is so disposed, the resiliency beingsufficient to accommodate for minor variations in yoke widths, and (d)attaching at least one mounting bracket to said casing and locatedagainst said yoke to securely fasten and hold said casing in the correctposition relative to said valve shaft.
 7. A method of mounting an alarmswitch as claimed in claim 6, including the further step of attachingsaid at least one mounting bracket to said yoke.